Groundwater Contamination with Organoarsenic Compounds


On an abandoned industrial production site for chemical warfare agents in Kapen (Saxony-Anhalt) a huge contamination with organic arsenicals (some milligram arsenic per liter) was found in the groundwater at the area of the former warfare storage tanks. Up to 80% of the total arsenic content are phenylarsenic compounds, especially phenylarsonic acid and diphenylarsinic acid.

The scientific investigations on the contaminated site were:

  • a pilot test for groundwater remediation within source area
  • analytical investigation for species analysis of the contaminants
  • depth orientated groundwater exploration by direct push technology at the source zone and the downstream plume
  • ecotoxicological tests with original groundwater samples and pure substances(in cooperation with the Dept. of Bioanalytical Ecotoxicology)

To elucidate the natural attenuation potential of phenylarsenic compounds microbiological degradation tests with contaminated groundwater-sediment-mixture were applied. The investigations with the autochthonous microorganisms include:

  • degradation tests under in situ conditions (anaerobic)
  • addition of electron acceptors to achieve nitrate and sulphate reducing conditions
  • addition of electron donors for stimulation of degradation processes
  • degradation tests under aerobic conditions

The objective of the work is to develop a concept for an in situ remediation or enhanced natural attenuation (ENA) for the contaminated site in Kapen to contribute to a sustainable improvement of groundwater quality.
The project is funded by the Landesanstalt für Altlastenfreistellung (LAF) of Saxony-Anhalt and the Deutsche Bundesstiftung Umwelt (grant 20007/919). The company CDM Consult GmbH acts as the site manager.